共查询到20条相似文献，搜索用时 31 毫秒
1.
K. I. Caputi R. J. McLure J. S. Dunlop M. Cirasuolo A. M. Schael 《Monthly notices of the Royal Astronomical Society》2006,366(2):609-623
We have selected and analysed the properties of a sample of 2905 Ks < 21.5 galaxies in ∼131 arcmin2 of the Great Observatories Origins Deep Survey (GOODS) Chandra Deep Field South (CDFS), to obtain further constraints on the evolution of Ks -selected galaxies with respect to the results already obtained in previous studies. We made use of the public deep multiwavelength imaging from the optical B through the infrared (IR) 4.5-μm bands, in conjunction with available spectroscopic and COMBO17 data in the CDFS, to construct an optimized redshift catalogue for our galaxy sample. We computed the Ks -band luminosity function and determined that its characteristic magnitude has a substantial brightening and a decreasing total density from z = 0 to 〈 z 〉= 2.5 . We also analysed the colours and number density evolution of galaxies with different stellar masses. Within our sample, and in contrast to what is observed for less massive systems, the vast majority (∼85–90 per cent) of the most massive ( M > 2.5 × 1011 M⊙ ) local galaxies appear to be in place before redshift z ∼ 1 . Around 65–70 per cent of the total assemble between redshifts z = 1 and 3 and most of them display extremely red colours, suggesting that plausible star formation in these very massive systems should mainly proceed in obscured, short-time-scale bursts. The remaining fraction (up to ∼20 per cent) could be in place at even higher redshifts z = 3–4 , pushing the first epoch of formation of massive galaxies beyond the limits of current near-IR surveys. 相似文献
2.
3.
4.
I. K. Baldry K. Glazebrook S. P. Driver 《Monthly notices of the Royal Astronomical Society》2008,388(3):945-959
A comparison between published field galaxy stellar mass functions (GSMFs) shows that the cosmic stellar mass density is in the range 4–8 per cent of the baryon density (assuming Ωb = 0.045 ). There remain significant sources of uncertainty for the dust correction and underlying stellar mass-to-light ratio even assuming a reasonable universal stellar initial mass function. We determine the z < 0.05 GSMF using the New York University Value-Added Galaxy Catalog sample of 49 968 galaxies derived from the Sloan Digital Sky Survey and various estimates of stellar mass. The GSMF shows clear evidence for a low-mass upturn and is fitted with a double Schechter function that has α2 ≃−1.6 . At masses below ∼108.5 M⊙ , the GSMF may be significantly incomplete because of missing low-surface-brightness galaxies. One interpretation of the stellar mass–metallicity relation is that it is primarily caused by a lower fraction of available baryons converted to stars in low-mass galaxies. Using this principle, we determine a simple relationship between baryonic mass and stellar mass and present an 'implied baryonic mass function'. This function has a faint-end slope, α2 ≃−1.9 . Thus, we find evidence that the slope of the low-mass end of the galaxy mass function could plausibly be as steep as the halo mass function. We illustrate the relationship between halo baryonic mass function → galaxy baryonic mass function → GSMF. This demonstrates the requirement for peak galaxy formation efficiency at baryonic masses ∼1011 M⊙ corresponding to a minimum in feedback effects. The baryonic-infall efficiency may have levelled off at lower masses. 相似文献
5.
6.
7.
8.
9.
10.
On the redshift cut-off for steep-spectrum radio sources 总被引：1，自引：0，他引：1
Matt J. Jarvis Steve Rawlings Chris J. Willott Katherine M. Blundell Steve Eales Mark Lacy 《Monthly notices of the Royal Astronomical Society》2001,327(3):907-917
We use three samples (3CRR, 6CE and 6C*) selected at low radio frequency to constrain the cosmic evolution in the radio luminosity function (RLF) for the 'most luminous' steep-spectrum radio sources. Though intrinsically rare, such sources give the largest possible baseline in redshift for the complete flux-density-limited samples currently available. Using parametric models to describe the RLF, incorporating distributions in radio spectral shape and linear size, as well as the usual luminosity and redshift, we find that the data are consistent with a constant comoving space density between and . We find that this model is favoured over a model with similar evolutionary behaviour to that of optically selected quasars (i.e., a roughly Gaussian distribution in redshift) with probability ratios of and for spatially flat cosmologies with and respectively. Within the uncertainties, this evolutionary behaviour may be reconciled with the shallow decline preferred for the comoving space density of flat-spectrum sources by Dunlop & Peacock and Jarvis & Rawlings, in line with the expectations of unified schemes. 相似文献
11.
12.
13.
Ignacio Ferreras Thorsten Lisker Anna Pasquali Sadegh Khochfar Sugata Kaviraj 《Monthly notices of the Royal Astronomical Society》2009,396(3):1573-1578
The evolution of number density, size and intrinsic colour is determined for a volume-limited sample of visually classified early-type galaxies selected from the Hubble Space Telescope /Advanced Camera for Surveys images of the Great Observatories Origins Deep Survey (GOODS) North and South fields (version 2). The sample comprises 457 galaxies over 320 arcmin2 with stellar masses above 3 × 1010 M⊙ in the redshift range 0.4 < z < 1.2 . Our data allow a simultaneous study of number density, intrinsic colour distribution and size. We find that the most massive systems (≳3 × 1011 M⊙ ) do not show any appreciable change in comoving number density or size in our data. Furthermore, when including the results from 2dF galaxy redshift survey, we find that the number density of massive early-type galaxies is consistent with no evolution between z = 1.2 and 0, i.e. over an epoch spanning more than half of the current age of the Universe. We find large discrepancies between the predictions of semi-analytic models. Massive galaxies show very homogeneous intrinsic colour distributions, with nearly flat radial colour gradients, but with a significant negative correlation between stellar mass and colour gradient, such that red cores appear predominantly in massive galaxies. The distribution of half-light radii – when compared to z ∼ 0 and z > 1 samples – is compatible with the predictions of semi-analytic models relating size evolution to the amount of dissipation during major mergers. 相似文献
14.
15.
16.
17.
Roberto De Propris Matthew Colless Simon P. Driver Warrick Couch John A. Peacock Ivan K. Baldry Carlton M. Baugh Joss Bland-Hawthorn Terry Bridges Russell Cannon Shaun Cole Chris Collins Nicholas Cross Gavin B. Dalton George Efstathiou Richard S. Ellis Carlos S. Frenk Karl Glazebrook Edward Hawkins Carole Jackson Ofer Lahav Ian Lewis Stuart Lumsden Steve Maddox Darren S. Madgwick Peder Norberg Will Percival Bruce Peterson Will Sutherland Keith Taylor 《Monthly notices of the Royal Astronomical Society》2003,342(3):725-737
18.
19.
Elaine M. Sadler Carole A. Jackson Russell D. Cannon Vincent J. McIntyre Tara Murphy Joss Bland-Hawthorn Terry Bridges Shaun Cole Matthew Colless Chris Collins Warrick Couch Gavin Dalton Roberto De Propris Simon P. Driver George Efstathiou Richard S. Ellis Carlos S. Frenk Karl Glazebrook Ofer Lahav Ian Lewis Stuart Lumsden Steve Maddox Darren Madgwick Peder Norberg John A. Peacock Bruce A. Peterson Will Sutherland Keith Taylor 《Monthly notices of the Royal Astronomical Society》2002,329(1):227-245
We have cross-matched the 1.4-GHz NRAO VLA Sky Survey (NVSS) with the first 210 fields observed in the 2dF Galaxy Redshift Survey (2dFGRS), covering an effective area of 325 deg2 (about 20 per cent of the final 2dFGRS area). This yields a set of optical spectra of 912 candidate NVSS counterparts, of which we identify 757 as genuine radio identifications – the largest and most homogeneous set of radio source spectra ever obtained. The 2dFGRS radio sources span the redshift range to 0.438, and are a mixture of active galaxies (60 per cent) and star-forming galaxies (40 per cent). About 25 per cent of the 2dFGRS radio sources are spatially resolved by NVSS, and the sample includes three giant radio galaxies with projected linear size greater than 1 Mpc. The high quality of the 2dF spectra means we can usually distinguish unambiguously between AGN and star-forming galaxies. We make a new determination of the local radio luminosity function at 1.4 GHz for both active and star-forming galaxies, and derive a local star formation density of . 相似文献
20.
Gabriella De Lucia Bianca M. Poggianti Alfonso Aragón-Salamanca Simon D. M. White Dennis Zaritsky Douglas Clowe Claire Halliday Pascale Jablonka Anja von der Linden Bo Milvang-Jensen Roser Pelló Gregory Rudnick Roberto P. Saglia Luc Simard 《Monthly notices of the Royal Astronomical Society》2007,374(3):809-822